Telephone transmitter



Ama 12, 1927. l 1,624,352

C. R. MOORE 'TELEPHONE TRANSMITTER File'd April 22. 1924 readily i pointof a number of `immovable electrodes Patented Apr.` l2, 1927.

Y' UNITI-:D STATI-:s

PATENT ",oFFlcE.

CHARLES B. MOORE,1 OF.WYOHING, NEW JERSEY, ASSIGNOB T0 WESTERN ELECTRICCOMPANY, INCORPORATED, 02E-'NEW YORK, N. Y., A CORPORATION 0F NEW YORK.

- TELEPHONE p'raansnrrrnn.

application mea April 22, im. serial Nq. 708,116.

- Thisinvention relates to microphone' transmitters, .and moreparticularly to a type'adapted for use Ain combination with asensitivereceiver` for the purpose of aiding deaf. persons to hear.

The ob]ect is' to provide-.anI instrument of this character which willbe simple, compact, cheap. to manufacture and efficient in use,'h'a vingcomparatively few parts which are assembled in such a manner as to beaccessible for purpose of repair, adjustment or substitution of parts.

In accordance with thisinvention, the a 'tatin member or diaphragm ismade o insu ating'material and contacts with resistance varying(material contained in depressionsor cups formed at the junction` andinsulating material. The terminals of the ltransmitter are preferablysecured to 'these-.,.electrodes Dueto this construction it is not'necessary to attach leads to the agitating member or diaphragm, thereby4permittin .the diaphragm to move more ac f' curately 1n accordance withits impressed,

frequencies. Referring to the drawings, Fig. 1 1s a front assembly viewof the transmltter with a portion-of the mouth piece and the diaphragmpartially cut away and Fig. 2 is a sectional view thereof. Similarreference characters refer -to similar parts throughout the severalviews.

This transmitter generally consists of a casing 10 .which may be ofnon-conducting material and Ain which concentricallyv arranged metallicelectrodes 11 "and '12 are sei. cured by means of a number of screwssuch .as 15 and 16` shown in Fig. 2.

-, The electrodes 1 1 and 12 are insulated from each other by means of aring 13 in-l terposed between the` linner and outer electrodes and whichmay be made of any sort 'of well known insulating material such as micaor hard rubber. These electrodes areinsillated from casing -10 by meansof an insulating disc 14. Screws 16 are each pro-` vided for fasteningthe wire terminals- 17 -and 18 of the electrodes and are insulated from.casing .10 by means; of insulating trodes 11 and v12 and insulating ring13 are eachl provided with a number of registering recesses adapted toform a plurality of preferably semi-spherical shaped cups 21, 22, etc.,which are each adapted to be filled with carbon granules as'shown inFig. 2.

On the edge ofcasing 10 and parallelto the plane surface of theelectrodes there is .mounted a diaphragm 23 which may be of any suitablenon-conducting material. This diaphragm is held `in adjusted position incontact with the carbon granules in.,A cups 21 -22etc., by means of themouth piece 24 which is preferably made of-insulating materialandvscrewed on the threaded ridge 25 of casing 10.

What is claimed is:

1. In'a telephone transmitter, a structure comprising immovableconcentric conducting sections separated 'by insulation and ture at thepoint of junction of said sections and insulation, a resistance varyingmedi- -m in said depressions for bridging said insli-lation, and anagitating member of insulating material directly in contact with saidresistance varying medium and spaced.

'junction point,. carbon' granules in said material cups, a diaphragm ofinsulatin directly in contactwith .the car on granules and spacedfromboth-electrodesand a terminalmountedA on each electrode.u

'having ldepressions formed in said struc- 4.- In a telephonetransmitter, the combi nation -with acasing, a plurality ofconcentricall disposed immovable electrodes arange in said casing, aninsulating rlng 1nbushings 19 and 20 respectively. The elec-4 lrposedbetween said electrodes, said eleci trodes. and ring formingdepressions at insulated from said casing and serving as their ]unct1onoints, a reslstance varying terminals.l medmm 1n sal depresslons forbridging In Wltncss whereof, I' hereunto subscribe 10 said insulatingring, a disc associated with my name this 16th day of Api-i1 A. D.,1924. said electrodes, and fastening means pass- .1924.

ing through said casing und disc and ipto A said electrodes, saidfastening means being CHARLES R. MOORE.

